Fermi estimate of time it takes to solve chess

Landauer limit 3e-23 J/bit in our current universe background radiation, with
$$kT\log 2, T = 3K, k = 1\times 10^{-23}J/(K\cdot bit)$$

Searching for game nodes has about 2e10 nodes/s on a GPU with 3e12 bits/s, so that gives about 100 bits/node.

The number of chess nodes needed to evaluate is about 1e43.

So we get an upper bound of 1e45 bits needed to solve chess, assuming we can't prune any nodes.

That requires 3e22 J at the Landauer limit.

Thoughts

If an embryo of two cells can be separated into two embryos, from which twins can develop, can this be continued more? So we get triplets, fourplets, fiveplets, etc.
And if that is so, would they have shorter lifespans due to cell division shortening the telomeres?

• Race against the machine
• Race with the machine
• Race into the machine
• Race of the machine

What would happen if sex organs are plug-and-play devices?

 - Well for starters it'd be pretty horrific if someone loses their vagina during pregnancy.
 - Maybe not so much. Hospitals would have emergency vaginas for that. Or just do cesarian.

1. All models are wrong, but some are useful. ---- George E. P. Box
2. Ethics are models of the world. ---- One possible stance of ethics 
3. All ethics are wrong, but maybe some are useful. ---- Conclusion

Fermi estimate: eccentricity of earth's orbit around the sun

I was reading about Tesla's rocket when I noticed some numbers.

Someone asked about the orbit of the car launched by the rocket Falcon Heavy in February 2018, and it said that

After orbiting the Earth for 6 hours, a third-stage burn-to-depletion was completed at approximately 02:30 UTC Feb 7, placing the dummy payload in a heliocentric orbit having a perihelion of 0.99 au and aphelion ~1.7 au.

and I thought, wait a pony picking minute, 0.99 au? Isn't earth "exactly" 1 au away from sun? Surely, the car got launched by accelerating from LEO, so when it enters the heliocentric orbit, its perihelion must be almost exactly the same as earth-sun distance.

Well, it's not precisely 1 au, and earth's orbit around the sun has eccentricity... Fermi estimate time!!!

Let's play: Fermi estimates

Fermi estimates are about getting rough guesses from as little data as possible. You win if you get it within a factor of 10.
I took the Fermi estimate problems from this site. You can read how it's done over there. I'll just record my own estimates here.

1. How many new passenger cars are sold each year in the USA?

• There are 3e8 people in America. Source: my memory.
• A citizen of a developed country lives 1e2 years. Source: common knowledge.
• About 1/2 Americans are rich enough to own cars. Source: A feely guess. 
• Each American car owner goes through 3 cars in their lives. Source: blind intuition. After the facts, I can justify by saying  a car usually breaks down in 20 years, and a person's adult life lasts about 60 years.

So in total, we get
$$(3e8 \text{ person}) * 1/2 * (3 \text{ cars/person }) * / (1e2 \text{ year }) = 4.5e6 \text{ cars/year}$$
The right answer is, according to Wikipedia:

In the year 2009, about $5.5$ million new passenger cars were sold in the United States according to the U.S. Department of Transportation.